Employ backend::lin_comb in mpi::subdomain_deflation
Employ backend::lin_comb in mpi::subdomain_deflation

ddemidov/amgcl,ddemidov/amgcl,ddemidov/amgcl,dondieselkopf/amgcl,ddemidov/amgcl,dondieselkopf/amgcl,dondieselkopf/amgcl